Softeners for fabrics, for example wovens, textile wovens, knits, nonwovens and/or fibers of natural and/or synthetic raw materials, are substances which impart a soft supple hand to the materials mentioned. Particularly suitable softeners are polysiloxanes with quaternary ammonium groups. By virtue of electrostatic attractive forces, the ionic groups anchor the siloxane to the fiber. In this way, friction is reduced and the desired softener effect is achieved. When the siloxane is applied in the form of microemulsions, it can additionally penetrate into the fiber and imparts inner softness and fullness thereto.
There are specific formulations for the care of damaged hair, such as hair rinses, hair repair treatments, shampoos, leave-on conditioners, etc., which in particular improve the compatibility, hand and shine of damaged hair. Such conventional haircare compositions comprise principally cationic surfactants based on alkylammonium, polymers, waxes or oils, or silicone oils. The efficacy of these compounds can be attributed to hydrophobization of the hair surface, among other causes.
For all these compositions, a good care action (conditioning) of the hair is achieved, but the appearance, especially the shine of the hair, is not improved by the care products, but in some cases even worsened.
There is therefore a need for versatile active ingredients for personal hygiene and care products, such as shampoos, hair treatment compositions and hair aftertreatment compositions, which, in addition to cleaning action, improve the care of the hair and simultaneously impart good shine, which protect the hair from damage to the hair structure and which minimize structural damage already caused to the hair, resulting from environmental influences and from shaping and coloring treatments.
Polysiloxanes with quaternary ammonium groups are known as additives for haircare. For example, DE 14 93 384, EP 0 017 122 and U.S. Pat. No. 4,895,964 describe structures in which siloxanes are modified with pendant ammonium groups distributed randomly over the polymer. These compounds have the disadvantage that they do not possess any marked silicone character, and good efficacy is not observed.
A more marked silicone character is possessed by cationic polysiloxanes as described in DE 37 19 086 and EP 0 294 642. In the structures described in DE 37 19 086 and in EP 0 294 642, the quaternary functions are bonded terminally to the polysiloxane. Such compounds offer advantages with regard to the action thereof as conditioners, both for hair and textiles and for hard surfaces. The use of such compounds in cosmetic formulations is described, for example, in EP 0 530 974, EP 617 607, EP 1 080 714, WO 2001/082879 and U.S. Pat. No. 6,207,141.
However, the structures described there possess only two cationic groups. Owing to the relatively minor electrostatic interaction of the polysiloxanes provided with two charge centers present at their termini, the affinity thereof for particular surfaces and, as a consequence thereof, also the substantivity thereof, i.e. the tendency thereof to become anchored permanently thereto, is comparatively low.
Polysiloxanes with pendant quaternary ammonium groups distributed randomly over the polymer and the use thereof as textile softeners are described, for example, in DE-B 14 93 384. These compounds have the disadvantage that they do not possess marked silicone character, and good efficacy as a textile softener is not observed.
A significantly more marked silicone character is possessed, in contrast, by cationic silicones as described in EP 0 294 642. EP 0 294 642 describes structures in which the quaternary functions are bonded terminally to a siloxane segment. When a textile is treated with such compounds, it receives good softness, but the siloxane is removable again easily from the corresponding textile owing to its low substantivity, for example by washing operations. In contrast to the domestic fabric softener, it is, however, desirable for industrial textile end finishing that the siloxane remains on the textile even after the wash and the softness is thus not lost.
Addressing the aspect of increased hydrophilicity, U.S. Pat. No. 5,807,956 and U.S. Pat. No. 5,981,681 claim nonhydrolysable block copolymers of the (AB)nA type with alternating units consisting of polysiloxane and amino-polyalkylene oxide, and a route for preparation thereof. For instance, noble metal-catalysed hydrosilylation produces SiC linkages of dihydrogenpolydimethylsiloxanes with olefins bearing epoxy groups, and the epoxy-terminated siloxanes thus obtained are reacted with amino-terminated polyalkylene oxides. Another alternative is the hydrosilylating linkage of α,ω-dihydrogenpolydimethylsiloxanes with epoxy-terminated allyl polyethers and the subsequent reaction of the epoxy-functionalized siloxanes thus obtained with diamines.
The teaching of WO 02/092904 relates to compositions consisting of nonhydrolysable block-type copolymers which do not possess an (AB)n structure, and which are obtained by the reaction between polydimethylsiloxanes A having epoxy groups and polyalkylene oxides B bearing epoxy termini in the presence of primary amines and/or mixtures consisting of primary and secondary amines. The presence of different epoxy substrates leads, in the presence of the aminic reactants, to a virtually uncontrollable, self-organized polyaddition process which, beyond an unachievable strict (A(amine)B)n structure, leads to a copolymer which, in varying population, has both homogeneously distributed (A(amine)A) and (B(amine)B) and heterogeneously distributed (A(amine)B) diades each linked aminically. Owing to the siloxane reactants provided with epoxy functions, the copolymer structures thus obtained are capable of linkage of the particular siloxanyl units via an ether function to the aminoorganic radicals of the copolymer. With the option of further elaboration for neutralization and/or quaternization, the substantivity for textile or fibrous surfaces can be adjusted. A disadvantage for use is the intrinsically high viscosity which is characteristic of these random copolymer structures.